U.S. Pat. No. 4,017,237 (Inventor: WEBSTER; Published: Apr. 12, 1977) discloses a mold provided with a pair of cavities interconnected by a runner to a common entry point. One of the cavities is gated whereby plastic may be injected into this cavity only by applying ultrasonic energy to the gate.
U.S. Pat. No. 4,120,921 (Inventor: WEBSTER; Published: Oct. 17, 1978) discloses a mold provided with a pair of cavities interconnected by a runner to a common entry point. One of the cavities is gated whereby plastic may be injected into this cavity only by applying ultrasonic energy to the gate.
U.S. Pat. No. 7,072,735 B2 (Inventor: SMITH; Published: Jul. 4, 2006) discloses a method and apparatus for controlling an injection molding machine having a first surface and a second surface including a piezo-ceramic sensor configured to be disposed between the first and second surface. The piezo-ceramic sensor is configured to sense a force between the first surface and the second surface, and to generate corresponding sense signals. Transmission structure is coupled to the piezo-ceramic sensor and is configured to carry the sense signals. Preferably, a piezo-ceramic actuator is also disposed between the first surface and a second surface, and is configured to provide an expansive force between the first surface and a second surface in accordance with the sense signals.
U.S. Pat. No. 7,165,958 B2 (Inventor: JENKO; Published: Jan. 23, 2007) discloses a method and apparatus provided for sealing interfaces within an injection mold having a first surface and a second surface including an active material actuator configured to be disposed in a manner suitable for generating a force between the first surface and the second surface. The active material actuator is configured to generate a force in response to sense signals from a transmission structure. Methods and apparatus are also provided for centering a nozzle tip within a gate opening, and adjusting tip height of a nozzle tip with respect to a gate opening, also using active material inserts.
U.S. Pat. No. 7,293,981 B2 (Inventor: NIEWELS; Published: Nov. 13, 2007) discloses a method and apparatus for compressing melt and/or compensating for melt shrinkage in an injection mold are provided. The apparatus includes a cavity mold portion adjacent a cavity plate, a core mold portion adjacent a core plate, a mold cavity formed between the mold portions, and at least one piezo-ceramic actuator disposed between either or both of the core plate and the core mold portion and the cavity plate and the cavity mold portion. A controller may be connected to the at least one piezo-ceramic actuator to activate it, thereby causing the mold cavity volume to decrease, compressing the melt.
United States Patent Application Publication Number 2005/0236725 A1 (Inventor: NIEWELS et al; Published: Oct. 27, 2005) discloses a method and apparatus for controlling an injection mold having a first surface and a second surface including an active material element configured to be disposed between the first surface and a second surface. The active material element may be configured to sense a force between the first surface and the second surface, and to generate corresponding sense signals. Transmission structure is coupled to the active material element and is configured to carry the sense signals. Preferably, an active material element actuator is also disposed between the first surface and a second surface, and is configured to provide an expansive force between the first surface and a second surface in accordance with the sense signals. The method and apparatus may be used to counter undesired deflection an/or misalignment in an injection mold.
United States Patent Application Publication Number 2005/0236726 A1 (Inventor: NIEWELS; Published: Oct. 27, 2005) discloses a method and apparatus for controlling a vent gap in a mold for an injection molding machine are provided, and include an active material insert configured to regulate the degree of opening of the vent gap. The active material insert is configured to be actuated in response to signals from a controller, so as to selectively block the opening of the vent gap during the molding process. Wiring structure is coupled to the active material insert, and is configured to carry the actuation signals. Melt flow sensors may also be provided to aid in regulating the vent gap, and may be connected to the controller in order to provide real-time closed loop control over the operation of the vent gap. Preferably, the methods and apparatus are used as part of a system for controlling the flow of melt within a mold cavity.
United States Patent Application Publication Number 2005/0236727 A1 (Inventor: NIEWELS; Published: Oct. 27, 2005) discloses a method and apparatus for applying a force to a portion of a surface of a mold component are provided. An injection mold has a core insert, a side acting core insert, and a piezo-ceramic actuator. The amount of force needed for sealing a surface of said side acting core insert to a portion of a surface of said core insert is determined, and a piezo-ceramic actuator is actuated so as to supply the force to seal the side acting core insert against the core insert during a molding operation. A piezo-ceramic sensor may be provided to sense a force between the side acting core insert an the core insert, and to generate corresponding sense signals. Wiring structure is coupled to the piezo-ceramic sensor and is configured to carry the sense signals.
United States Patent Application Publication Number 2005/0236729 A1 (Inventor: ARNOTT; Published: Oct. 27, 2005) discloses a method and apparatus for applying a vibration and/or oscillation to melt within an injection mold including at least one stable surface within the mold, at least one movable surface within the mold, at least one active material element affixed to each stable surface, and adjacent to each movable surface. In use, a control means repeatedly energizes the at least on active material element, wherein the repeated energizing of the at least one active material element generates vibration and/or oscillation in the melt. In the method, at least one active material element is activated intermittently to move the at least one movable surface with respect to the at least one fixed surface. In the apparatus, a wiring conduit is coupled to the active material insert, and is configured to carry vibration signals to the at least one active material element.
United States Patent Application Publication Number 2005/0238757 A1 (Inventor: NIEWELS et al; Published: Oct. 27, 2005) discloses a method and apparatus for assisting the ejection of molded parts from a mold having a first surface and a second surface including an active material actuator configured to be disposed between the first surface and a second surface. The active material actuator is configured to provide an expansive force between the first surface and the second surface in response to actuation signals, pushing the surfaces apart. Transmission structure is coupled to the active material actuator and is configured to transmit the actuation signals. The molded part may be ejected upon initiation of the actuation signal, or upon withdrawal of the actuation signal.